HKS Metal Head Gasket NA (Subaru BRZ / Scion FR-S 13+) 23001-AT002
Maintain a high seal with high pressure!
Both types are endurable against high engine output.
Stopper structure of the bore seal is separated type so it prevents leakage even under high gas-pressure at high engine output.
Compression Ratio for an NA engine is increased!
The t0.5 type (SC install able) for an NA engine was designed to increase the compression ratio compared to a stock gasket as well as seal durability. Also, it is thinner than a stock. It is the best to use for one make race with an NA engine. Compression ratio of the gasket for an NA engine is 12.6. Its thickness is t0.5. (Stock compression ratio is 12.5 and thickness is t0.6.)
Contact surface pressure is improved!
Special coating was applied on the head side and cylinder side to improve sealing performance when tightening the bolts.
Bore seal pressure was confirmed in figures. (See the diagram)